traitCollecting[E, C] extends AnyRef

A Collecting[E, C] provides access to the "collecting nature" of type C in such
a way that loneElement syntax can be used with type C. A C
can be any type of "collecting", a type that in some way collects or brings together elements of type E.
ScalaTest provides implicit implementations for several types. You can enable the contain matcher syntax
on your own type U by defining an Collecting[E, U] for the type and making it available implicitly.